Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jun 25;21(1):606.
doi: 10.1186/s12879-021-06326-x.

Mortality in Escherichia coli bloodstream infections: a multinational population-based cohort study

Melissa C MacKinnon  1 , Scott A McEwen  2 , David L Pearl  2 , Outi Lyytikäinen  3 , Gunnar Jacobsson  4   5 , Peter Collignon  6   7 , Daniel B Gregson  8   9 , Louis Valiquette  10 , Kevin B Laupland  11   12   13
Affiliations

Mortality in Escherichia coli bloodstream infections: a multinational population-based cohort study

Melissa C MacKinnon et al. BMC Infect Dis. .

Abstract

Background: Escherichia coli is the most common cause of bloodstream infections (BSIs) and mortality is an important aspect of burden of disease. Using a multinational population-based cohort of E. coli BSIs, our objectives were to evaluate 30-day case fatality risk and mortality rate, and determine factors associated with each.

Methods: During 2014-2018, we identified 30-day deaths from all incident E. coli BSIs from surveillance nationally in Finland, and regionally in Sweden (Skaraborg) and Canada (Calgary, Sherbrooke, western interior). We used a multivariable logistic regression model to estimate factors associated with 30-day case fatality risk. The explanatory variables considered for inclusion were year (2014-2018), region (five areas), age (< 70-years-old, ≥70-years-old), sex (female, male), third-generation cephalosporin (3GC) resistance (susceptible, resistant), and location of onset (community-onset, hospital-onset). The European Union 28-country 2018 population was used to directly age and sex standardize mortality rates. We used a multivariable Poisson model to estimate factors associated with mortality rate, and year, region, age and sex were considered for inclusion.

Results: From 38.7 million person-years of surveillance, we identified 2961 30-day deaths in 30,923 incident E. coli BSIs. The overall 30-day case fatality risk was 9.6% (2961/30923). Calgary, Skaraborg, and western interior had significantly increased odds of 30-day mortality compared to Finland. Hospital-onset and 3GC-resistant E. coli BSIs had significantly increased odds of mortality compared to community-onset and 3GC-susceptible. The significant association between age and odds of mortality varied with sex, and contrasts were used to interpret this interaction relationship. The overall standardized 30-day mortality rate was 8.5 deaths/100,000 person-years. Sherbrooke had a significantly lower 30-day mortality rate compared to Finland. Patients that were either ≥70-years-old or male both experienced significantly higher mortality rates than those < 70-years-old or female.

Conclusions: In our study populations, region, age, and sex were significantly associated with both 30-day case fatality risk and mortality rate. Additionally, 3GC resistance and location of onset were significantly associated with 30-day case fatality risk. Escherichia coli BSIs caused a considerable burden of disease from 30-day mortality. When analyzing population-based mortality data, it is important to explore mortality through two lenses, mortality rate and case fatality risk.

Keywords: Bacteremia; Bloodstream infection; Case fatality; Escherichia coli; Mortality; Mortality rate; Population-based.

PubMed Disclaimer

Conflict of interest statement

MCM reports a scholarship from the Canadian Institutes of Health Research and funding for a Federal Student Work Experience Program placement from the Government of Canada – Genome Research Development Initiative, both related to her PhD program and outside the submitted work. LV reports being a stock holder of Lumed Inc., outside the submitted work. All other authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Number of 30-day deaths in E. coli bloodstream infection patients by age category and sex
Fig. 2
Fig. 2
Directly age and sex standardized E. coli bloodstream infection 30-day mortality rates by areaa Abbreviations: 3GC-R – Third-generation cephalosporin-resistant; 3GC-S – Third-generation cephalosporin-susceptible. aStandard population – EU28 2018 population
Fig. 3
Fig. 3
Directly age and sex standardized E. coli bloodstream infection 30-day mortality rates by yeara. Abbreviations: 3GC-R – Third-generation cephalosporin-resistant; 3GC-S – Third-generation cephalosporin-susceptible. aStandard population – EU28 2018 population
See this image and copyright information in PMC

References

    1. Skogberg K, Lyytikainen O, Ollgren J, Nuorti JP, Ruutu P. Population-based burden of bloodstream infections in Finland. Clin Microbiol Infect. 2012;18(6):E170–E176. doi: 10.1111/j.1469-0691.2012.03845.x. - DOI - PubMed
    1. Nielsen SL, Pedersen C, Jensen TG, Gradel KO, Kolmos HJ, Lassen AT. Decreasing incidence rates of bacteremia: a 9-year population-based study. J Inf Secur. 2014;69(1):51–59. - PubMed
    1. Bonten M, Johnson JR, van den Biggelaar AHJ, Georgalis L, Geurtsen J, de Palacios PI, et al. Epidemiology of Escherichia coli bacteremia: a systematic literature review. Clin Infect Dis. 2020;72:1211. doi: 10.1093/cid/ciaa210. - DOI - PubMed
    1. Laupland KB. Incidence of bloodstream infection: a review of population-based studies. Clin Microbiol Infect. 2013;19(6):492–500. doi: 10.1111/1469-0691.12144. - DOI - PubMed
    1. Tom S, Galbraith JC, Valiquette L, Jacobsson G, Collignon P, Schonheyder HC, et al. Case fatality ratio and mortality rate trends of community-onset Staphylococcus aureus bacteraemia. Clin Microbiol Infect. 2014;20(10):O630–O632. doi: 10.1111/1469-0691.12564. - DOI - PubMed